Car truck



Aug. 31,1937. R. c. HOBSON 2,091,853 CAR TRUCK Filed March 25, 1934 5Sheets-Sheet 2 INVENTOR: Boyd/{055020 BY MAS 'BwATTo NEY M 4 1, M H 0M 7l l l nul Aug. 31, 1937. R. c. HO-BSON 2,091,853

cm TRUCK 7 Filed March23, 1934 5 Sheets-Sheet a III/'IIIIIIIIIIINVENTOR.

Aug. 31, 1937. R. c. HOBSON CAR TRUCK Filed March 25, 1934 5sheets-sheets INVENTOR: 'Royflbso/b BAY ATTORNEY Patented Aug. 31,1937 4I 7 2,091,853

UNITED STATES PATENT "OFFICE CAR TRUCK as c. nobson, Cleveland Heights,Ohio, assignor to National Malleable and Steel Castings Company,Cleveland, Ohio, a corporation of Ohio Application March 23, 1934,Serial No. 116,948 32 claims. (01. 105-197) This invention relates torailway car trucks. view showing a further modification of the in- Oneof its objects comprises novel bolster-supvention.

porting provisions whereby loads or forces are Fig. 11 is a transversevertical sectional view transmitted from the bolster to the side framesin on line I l--i I of Fig. 10.

; a particularly advantageous manner, with drastic Fig. 12 is ahorizontal section on line l2-l2 of 5 reduction in bending moments and.secondary Fig. 11, but with the spring plank omitted.

bending stresses 'in'thetension and compression Referring to thedrawings, there is shown in portions and columns of the side frames. TheFig. 1 a car truck side frame A comprising a cominvention furtherprovides new and highly eflecpression member 2, inclined tension members3.

tive means for damping oscillations ofthe bolv3, a lower horizontaltension portion 4, and 10 ster-supporting springs. A further feature ofcolumns 5. 5 jo n n he compr s on member 2 i the invention resides inprovisions for transnd te s Portion d Providing a bolstermittingbolster-supporting spring stresses to the receiving op i d wtherebetween- The sides of the bolster for snubbing or dampingbolsterBextends at one end into said opening.

15 spring'oscillations. The invention also, enables t l be und rst d hatt car u k als i 15 Wheel change or .disassembly of the truck to becludes a similar side frame into which the oppoaccomplished with markedfacility, permits a site end of the bolster projects, but a descriptionsubstantialsgvlng in m, and provides 5 of one side frame and itscooperation with the tively' for squaring of the side frames withrespect bolster is suflicient for an unders n n f my to the bolster inresponse to departure of aid id invention. The bolster B is of theconventional 20 frames from such relation, as in rounding curves.American Railway Association yp ha Pairs The foregoing advantages,moreover, are attained u 5 a 1 at h n thereof, adapted without requiringany change in construction of t cooperate with 0119081118 Sides of the00111111113 the conventional American Railway Association 0fthvconventional A- R- A S fr m w bolst r Other features and advantagesof the such frame is employed with the bolster, as iswell 25 inventionwill be hereinafter described and t od At its pp s te e ds e side frameclaimed. A cooperates with journal boxes for the truck In theaccompanying drawings: wheel axles in the customary manner, one of Fig.1 is a view partly in side elevation and Said journal boxes b61118 nd td at 0 partly in vertical section, showing a portion of a In c ry n oumy i v n io 1 pr v e a pair car truck embodying my invention. of rockermembers in the form of bell crank levers Fig. 2 is a horizontalsectional .view taken on 9; t e Short Horizontal arms 9' of whichunderline 2-2 of Fig. 1, the bolster being shown in plan. he a s at m mbr III whi h carries the b ster Fig. 3 is a vertical sectional view'takenon line Supporting Springs IL Each of t Kickers 9 is 3-3 of Fig. 1, thebolster being h w 1;; id pivotally mounted in the side frame through the36 elevation. medium of intermediate curved portion 9" of the Fig. ,4 isa fragmentary side elevational view rocker which seats in muespondmglycurved illustrating a mode of disengagement of the' 90mm the side frameasnubbing levers from the bolster, preparatory to amresa'id is Shownbelow a corresponding- 40 disassembly of the truck. one of the columns 5and in the region wherein 40.

Fig.- 5 is a horizontal sectional view withthe the mflmntal tensionmerges with an bolster in plan, illustrating the squaring actionadjacent tensmemember The u are upon a side frama channel shaped incross section, as shown particularly in Fig. 2, and the long arms of theg 6 is diagramm tic elevation View rockers 9 extend through the opensides of said 'tratingthe transmission of "stresses through the columnsinto the bolstr receiving opening The bflster supmmng springs the side.short arms 9' project upwardly through the open 7 is fragmentaryvertical longmmmal side 'of the tension portion 4, for engagementsectional view showing a modified form of my inwith spring seat "L Thelatter rests upon Ventionportions 0" of the arms-9', said portions 9"be- Fig. 8 is a transverse vertical sectional view on in'g curved orcrowned, as shown, to enable the in e rockers and spring seat to engageat substantially Fig. 9 is a horizontal sectional view on line 9-9 thesame point regardless of variations in the of Fig. 8. rocker and springseat castings arising in the f Fig. 19 is a fragmentary longitudinalsectional manufacture thereof.

The sides 5' of each of the channel shaped columns 5 merge at theirupper ends with the side walls of the channel shaped compression member2, and at their bottoms with the side 5 walls 4', 4 of the horizontaltension member 4, said sides 5, 5' also merging with the side wallsofthe adjacent channel shaped and inclined tension member" 3. Also theback wall 5" of each of said columns 5 extends downwardly from thecompression member 2, and merges with the bottom wall 3' of the adjacenttension member 3, as well as with the adjacent curved wall I2, whichforms an end portion of the bottom wall 4" of the horizontal tensionmember 4.

The spring seat I 0 has projections I3, I3 depending therefrom into thespace within the side frame tension portion '4. Between theseprojections is a web I4 integral with said tension portion 4 andextending across the top thereof,

from one side wall to the other.

cooperation with the spring seat projections I3, I3, maintains saidspring seat in properly centered relation in the side frame windowopening.

The upper portion of the long arm of each rocker 9 may engage directly aside wall of the bolster but preferably, as shown, wear plates I5, I5are interposed between said bolster and the respective rockers. Eachwear plate I5 is mounted between a corresponding pair-of bolster lugs 6,6 or I, I, and is provided with flanges I5, I5

engaging the top and bottom of the bolsten. The.

portion of each rocker arm which engages the associated wear plate I5 ispreferably thickened as shown at I6 and is received between side flangesI5", I5" of said. Wear plate.

A spring plate I I may be interposed between the bolster and the tops ofthe springs II, while a plate I8 is shown between the bottoms of saidsprings and the seat member I0. An upwardly 40 extending peripheralflange ID" on said seat member surrounds said springs :and maintainsthem in position on said member I0.

From the foregoing description it will be-seen that the forces impartedby the bolster to the springs II upon which said bolster rests, aretransmitted through the seat member II) to the rockers 9, 9, and thatthrough the frictional engagement between the long arms of -said ockersand the plates I5, I5 at the bolster sides, scilla., tions of thesprings are quickly snubbed or damped. My construction thus provideseffectively for the prevention of undesirable harmonic oscillations ofthe bolster supporting springs, which oscillations frequently endangerthe car and its lading. The frictional engagement between said rockersand wear plates furthermore aids the springs in cushioning heavy shocks,in addition to dampening oscillations and preventing sudden springrecoil. It will further be observed that through the provision of therockers 9 the'bolster is enabled to move vertically without rubbingagainst the side frame columns. Wear between the bolster and side frameis thus reduced to a minimum. The wear plates I5 and rockers 9 may be ofany appropriate wear-resistant metal, such as any steel havingsubstantial wear-resisting properties.

Each of the side frame columns 5 is shown provided with flanges I9extendinglaterally from opposite sides thereof. These flanges projectinto position for receiving accelerating or. braking thrusts from thebolster lugs 6, 6 or 1, I. In addition, the flanges I5" of the wearplates transmit thrusts of the type aforesaid to the side frame columns,said flanges I5" thus increasing the Said Web, in 7 area forthetransmission of such stresses to the side frame. Y

The inner surface of each wear plate is preferably curved slightlyvertically, as shown at I5', assuring an extended bearing between theouter surface of the wear plate and the associated rocker arm despitevariations in the adjacent surfaces of the wear plate and bolster.

Since the wear plates are mounted between the respective pairs ofbolster lugs 6, 6 and -'I, I, 11 and each rocker 9 in turn extendsbetween the flanges I5" of the associated wear plate, it will be seenthat through said lugs, flanges, and rockers, the bolster is maintainedinassembled relation to the side frames. Disassembly of the 1'! truckfor wheel change purposes or otherwise may at the same time beaccomplished expeditiously as follows: 1 v The bolster is raisedslightly into -a position such as shown in Fig. 4, and is held in thatpo- 2( sition by suitable blocking. -Wedges .20 are then insertedbetween the rockers 9 and the adjacent springs II, throwing said rockersoutwardly clear of the wear plate flanges I5". Then, following removalof the journal box wedges 'and brasses 25 in the customary manner, theside frame can be readily slipped off the bolster. It may be noted inthis connection that the upper .part of the bolster receiving opening inthe side frame A herein disclosed is wider than that of the con- 30ventional A. R. A. side frame, and that the bolster lugs 6, 6 and I, 1do not overlie the sides of' the frame adjacent said opening. Instead,said lugs lie entirely between the side frame'columns 5. The side framemay thus be freely 5 moved-sideways to clear the bolster.

The clearance between the bottom of the spring seat I0 and the top ofthe horizontal tension member is ample to require very substantial andprolonged wearing away of the wear plates I5 be- 40 .fore said springseat engages said tension mem r 'As is illustrated in Fig. 5, theinvention provides automatically and effectively for squaring of theside frames with respect to the bolster. 45

Whenever for any reason (as, for example, in rounding curves) one sideframe tends to lead the opposite'one the bolster wear plates are engagedby opposite corners of rockers 9. Thus, as shown in Fig. 5, the sideframe A is out of squared 60 relation-with the bolster, the longitudinalaxis of the bolster being designated X and that of the 4 side framebeing shown by line Y. A line perpendicular to line Y is shown at X,indicating 'in conjunction with line X the extent to which 55 the sideframe and bolster are out ofsquared relationship. It will be seen thatthe left hand wear plate I5 is engaged by the corner 9 of the adjacentrocker 9, while the right hand wear plate is engaged by corner 9' of itsassociated, 60 rocker. Said rockers, under the influence of the springsI I, thus exert a couple urging the return of the side frame intosquared relation to the bolster.

A further important feature of my invention 65 resides in a novel andhighly advantageous transmission of forces from the bolster to the sideframe. Referring to Figure 6, there is illustrated the transmission offorces from the bolster to the side frame through one of the rockers. 9.7 The force applied to the shortarm of the rocker. at projection 9" isillustrated by the vector CD, and the reaction between the side of thebolster and surface I6 of the rocker by vector CE. The resultant ofthese forces is indicated by the lin 75 on; It will be aoansas notedthat the line of; action of the resultant of the bolster forces-passesclosely adjacent to the point G. The latter has at the intersection oflines HG, IG, and JG, which constitute the gravity axes respectively ofthe inclined tension member 3, the-side frame column 5, and thehorizontal tension portion 4. In other imum limiting words, the line HGpasses through the centers of gravity of successive cross sections ofmemher 3 perpendicular to the longitudinal axis thereof; line IG passesthrough the centers of gravity of successive cross sections of column 5;

and line JG through the centers of gravity of successive cross sectionsof tension portion 4.

By virtue of the close proximity of the line of action of the resultantCF to the point G it will be seen that practically no. bending moment isapplied by the bolsterto any of the members 3, 4, and 5, or to thecompression member 2. The

' 20 foregoing analysis applies equally to the transthe bolster throughthe side'frame. This force mission of forces from other rocker 9 in thetransmission is in marked contrast to those prevailing in conventionalside frames, wherein the resultant of the bolster weight passes throughthe centratregion of the horizontal tension portion of the side framewith consequent production of a decided beam action involving powerfulsecondary bending stresses tending to distort said horizontal tensionportion together with the tension and compression members and the sideframe columns. The direction of the resultant of the bolster stresses inmy construction above described may be varied by changing the relav ofthe rocker 9.

Owingto the substantial elimination of bendingmoments as abovedescribed, I am enabled to materially reduce the various members andstill maintain the stresses within them well below the A. R. A.maxspecifications. Side frames employed with my invention may be oflighter construction with consequent reduction in weight in Y rockers 9increases with the car trucks. Also, due to the maintaining of thebolster and side frames in assembledrelation through the rockers 9 incooperationwith the'bolster lugs'ii, 6 and 1,1, the necessity of aspring plank is avoided and the latter can be the cross-sectional areaof omitted, with further saving in weight. For example, for a 40 ton,car a saving of ap roximate- 1y 250 pounds in car truck weight may beeffected through my invention, while for 50 ton cars a saving of about4'70 pounds per car may be at- -tained.. j l It may be further observedthat the frictional pressure betweenithe sides of the bolster and thethe extent of compression of the springs II, the damping action of thefriction systemthus'being proportional to the load upon said'springs.Also the couple, hereinbefore described in connection with Fig. 5,

which tends to restore the bolster'and side frames in Figures 7, 8,and9.

into squared relation to each other, increases in magnitude with theload upon said springs. My invention may, if desired, be employed inconjunction. with a spring plank, as illustrated In these views the sideframe,ybolster, rockers the same as in the. preceding views. the bolstersupporting However,

- ner. The spring plank-is engaged plank in assembled relation to theside frame.

plank directly engages opposite end of said spring plank coacts with thecorresponding side frame in the same man- I with the springv seat Itthrough lugs 22 projecting upwardly from said seat through openings '23punched in 5 said plank. Depending flanges 24, 24 on the spring seat l0overlap opposite sides of the hori- 'zontal tension portion 4 of theside frame,-maintaining the spring seat and attached spring In Figs.10,11, and 12 there is shown a further modification of my inventionwherein the spring seat of Figs. 7, 8, and 9 is omitted, and the springthe rockers 9. Thus the spring plank 2| in Figs. 10, 11, and-12 bearsdi- 15 rectly on said rockers 9. While lugs or dowels might be providedon the side walls of the horizontal tension member 4 for engagement with,of such terms. and expressions, of excluding any equivalents of thefeatures shown and described or portions thereof, but recognize thatvarious modifications are possible within the scope of the inventionclaimedfi I I claim:

1. In a car truck, a side'franie, a bolster, springs beneath saidbolsterfor supporting the same, and means i on said side frame forsupporting said springs and exterting frictional pressure againstthe=sides of said bolster under the influence of said springs.

2. In a cartruck, a side frame, a bolster, springs supported by saidside frame beneath said bolster 40 for supporting the latter, andsnubbing means ;on said side frame for generating friction inconjunction with the sides of said bolster under, the

pressure of said springs.

3.-In a car truck, a side frame, a bolster, a

pair of rocker members on said side frame, and means comprising bolstersupporting springs carried by said members for causing saidm'emberstoexert frictional pressure against the sides of said bolster. I a 4. In-a car truck, a side frame, a bolster, springs'beneath said bolster forsupporting the same, and snubbing means for said springs comprising. apair of rockermembers on said side frame, said rocker members havinghorizontal arms extending under said springs and vertical arms forced bysaid springs to exert pressure against the sides of said boister.

5. In a cartruck, a side frame, a bolster springs beneath said bolsterfor supporting the I same, a pair of rockefmembezseach having ahorizontal arm and, a vertical arm and pivotally mounted intermediateits ends on said side frame, said horizontal arms receiving forces fromthe bolster through' said prings and said vertical arms transmittingpressure to the sides of said bolster.

9, and wear plates- I5 are 6. In a car truckfa side frame comprising an1 upper compression member, alower tension memsprings I l,'together'with Q the spring plate l8, are mounted on asspringplank 2|.The latter extends, from one of the truck to'the other, but adescription, of the end portion thereof associated with the side frameAwill suffice, it being understood that the side frame ber, and columnsconnecting said members and.

providing a bolster receiving opening therebetween; 'a' bolsterextending into said opening, spring means underlying said bolster forsupporting the same, a pair of rockerelements each bearing against saidside frame in an end por- -'75 tion of said tension member, each rockerhaving an arm receiving forcesfrom said bolster through said springmeans and a vertical arm exerting pressure against a side of saidbolster, the direction of the resultant of the forces applied by thebolster to each rocker passing through the region adjacent a point atthe intersection of the gravity axis of the tension member and thegravity axis of the correspondingcolumn.

7. In a car truck, a side frame comprising an upper compression member,a horizontal tension member, and columns connecting said members andproviding a bolster receiving opening therebetween; a bolster extendinginto said opening;

spring means beneath said bolster for supporting.

thesame; and means interposed between said spring means, the sides ofsaid bolster, and said tension member for causing the resultants of thebolster forces to extend along lines passing through the respective endportions of said tension member adjacent the bottoms of the respectivecolumns.

8. In a car truck, a side frame comprising an upper compression member,a lower tension member, and columns connecting said members andproviding a bolster receiving opening therebetween; a bolster extendinginto said opening; spring means below said bolster for supporting thesame; said tension member having curved portions below the respectivecolumns; a pair of rocker members each having a horizontal arm, avertical arm, and an intermediate curved portion seated in acorresponding one of the curved portions of said-tension portion, thehorizontal arm of each rocker extending under said spring means forreceiving forces therefrom, and the vertical arm of each rockerprojecting upwardly within a corresponding one of said columns andextending inwardly beyond said column into position for applyingpressure to a side of said bolster.

9. In a car truck, \a side frame comprising an upper compression member,a lower tension member, and columns connecting said ,members andproviding a bolster receiving opening therebetween; a bolster extendinginto said opening; spring means below said bolster for supporting thesame; a pair of rocker members each pivotally mountedin a correspondingend portion of said tension member, each rocker member hav-- ing ahorizontal arm underlying said spring means for receiving forcestherefrom, and each rocker member also having a vertical arm projectingupwardly within a corresponding one of said columns and extendinginwardly beyond said column into position for applying. pressure to aside of saidbolster.

'10. In a cartruck, a side frame comprising'an uppercompression member,a lower tension mem- 60 ber, columns connecting said members andproviding a bolster receiving opening therebetween and inclined tensionmembers extending fromopposite'ends of said lower tension member toopposite end portions of said compression member, said inclined tensionmembers having bottom walls merging with the end portion of the bottomwall of said lower tension member, and said columns each having avertical wall extending downwardly and merging with the bottom wall-ofaninclined tension memberadjacent an end portion of said lower tensionmember, the end portions of the bottom wall of said lower tension memberbeing curved; a bolster extending into said'openi'ng; spring .meansbeneath said bolster for supporting the same; a pair of rocker memberseach having a curved portion seated in a corresponding curved endportion of said lower tension member, each rocker member having an armextending beneath said spring means for receiving forces therefrom andalso having an arm projecting upwardly within a corresponding column andextending inwardly beyond said column into position for applyingpressure to a side of said bolster.

11. In a car truck, a side frame comprising an upper compression member,a horizontal tension member, and columns connecting said members andproviding a bolster receiving opening therebetween, said columns eachcomprising side walls and a back wall merging into said tension member,a bolster extending into said opening, vertically disposed spring meansfor supporting said bolster, and means cooperating with said springmeans for transmitting forces obliquely from the bolster to the sideframe at points adjacent the junctions of said. tension member and saidcolumns.

12. In a car truck, a side frame comprising an upper compression member,a lower tension member, and columns connecting said members andproviding a bolster receiving opening therebetween, a bolster extendinginto said opening, vertically disposed spring means for supporting saidbolster, and means cooperating with said spring means fortransmittingstressesobliquely from the bolster to the side frame atpoints in the end portions of said tension member.

13. In a car truck, a side frame comprising an upper compression member,a lower tension member, columns connecting said members and providing abolster receiving opening therebetween, inclined tension membersextending from opposite ends of said lower tension member to oppositeends of said compression member, a bolster extending into said opening,spring means beneath said bolster for supporting the same, and meanscooperating with said spring means for transmitting stresses obliquelyfrom said bolster to said side frame adjacent the intersections of thegravity axes of said tension members and cola side frame and havingportions extending'into position for applying pressure to the sides ofthe bolster under the influence of said springs.

15. In a car truck, a side frame, a bolster, spring means beneath saidbolster for supporting the same, a spring-seating member on which saidspring means 'is mounted, a pair of rockerelements each comprising anintermediate curved portion fulcrumed on a correspondingly curvedportion of the side frame, each rocker element also comprising a portionunderlying and supporting said spring seating member, and a verticallyextending portion for transmitting pressure to a side of thetbolster.

16. In a' car truck, a side frame comprising an upper compressionmember, a lower tension memspring means is mounted, rocker means mountedon said side frame'for supporting said seating means andtransmitting-pressure to the sides of, the bolster, said lower tensionmember comprising a bottom wall and upwardlyextending side-walls havinga web extending thereacross, said spring seating member havingprojections extending downwardly therefrom on opposite sides of saidweb.

1'7. In a car truck, a side frame, a bolster,

, spring means supported by said side' frame below means, comprisingrocker elements mounted in 5 plank, interengaging is, mounted, meanscomprising a pair of elements porting .said

said side frame and having portions cooperating with said lugs formaintaining the bolster and side frame in assembled relation, saidrockers also having portions underlying said spring means.

19. In a car truck, a side frame, a bolster having an end portionextending into said side frame, said end portion havingspaced lugs oneach side thereof a. pair of plates carried by said bolster andextending between the respective pairs of lugs, spring means on saidside frame for supporting said bolster and rocker elements receivingstresses from thelbolster through said spring means and engaging saidplates.

20. A car truck, a side frame, a bolster, spring means beneath saidbolster for supporting the same, a spring plank on'which said springmeans is mounted, and means comprising a pair of elements fulcrumed onsaid side frame for sup-'- porting said spring plank. I

'21. A car truck, a side frame, abolster, spring means beneath saidbolster for supporting the same, a'spring plank on which said. springmeans is mounted, and means-comprising a pair of elements pivotallymounted in said side frame for supporting said spring plank, saidelements having portions underlying said spring plank and portionsoverlying opposite-sides of the bolster 6 for applying pressure thereto.s 22. In a car truck, a side frame, a bolster, spring means beneath'saidbolster for supporting the same, a spring plank on which said springmeans is mounted, a member underlying said spring plankand said member,a pair of elements pivotally mounted in the side frame, and havingportions underlying said member for supporting the same, said elementshaving portions'extending pressure thereto. I 1

23. A car truck, a sideframe, a bolster, spring means beneath saidbolster for supporting the same, a spring. plank on which said springmeans pivotally mounted in said side frame for sup- 17 same, a springplank on which said spring means plank-and said member,

exerting pressure upon oppoand means on said .side

' porting I spring nieans between said spring 3 along opposite sides.of. the bolster for applying spring plank, said elements having.

portions underlying said spring plank and por tions overlying oppositesides of the bolster for- -7 appl ng pressure thereto, and-means formaintaining said spring plank in'assembled relation to is mounted, amember underlying said spring plank, interengaging means between saidspring a pair of elements pivotally mounted in the side frame, andhaving portions underlying said member forsupporting the same, saidelements having portions extending along opposite sides of the bolsterfor applying pressure thereto, and interengaging means between saidspring plank and said member, said member having projections overlappinga por-,

' tion of the side frame for maintaining said memher in a given relationto said side frame.

25.'In a car truck, a side frame, a bolster, springs supported, by saidside frame directly beneath said bolster for supporting the latter,frame for exerting frictional pressure against thesides of said bolsterunder the influence of 'said springs, said pressure being proportionalto the bolster load upon said springs.-'

26. In a car truck, a side frame, a bolster, spring means'direetly belowsaid bolster for supsaid spring means and exerting pressure uponopposite sides of said bolster for-applying [a couple to said bolster torestore the side frame and bolster into square relationship upon de'-parture therefrom.

27. In a car truck, a side frame, a bolster,

means directly below said bolster for supporting the same, and meanscooperating with said spring means and exerting pressure upon oppositesides of said bolsterfor applying a couple to said bolster to restorethe side frame and bolster into-square relationship upon departurethere- -from,,.said pressure being proportional to the bolster load uponsaid spring means.

' 28. In a car truck, aside frame, a bolster, spring 7 means below saidbolster for supporting the same,

and means comprising rocker'elements cooperatingwith said spring meansand exerting pressure upon opposite sidesofsaidibolster'for applyingacouple to said bolster to restore the side frame and bolster intosquared relationship upon departure therefrom, said pressure beingproportional to the bolster load upon said spring means.

29. In a car truck assembly, a bolster, side frames! assobiatedwith saidbolster at the ends thereof, vertically disposed springs supportingsaidbolste'r on said side frames, and means betweensaid springs and'said' side frames and cooperating with the bolster to compress at leastone of said springs when said bolster is moved longitudinally withrespect to said side" frames.

. 30. In a car truck assembly, a bolster, side frames associated withsaid bolster at the ends 'thereof, vertically disposed springssupporting said bolster on said side' frames, andmeans between saidsprings and said side frames and cooperating with the bolster tocompress atleast one ofsaid springs an amount proportional to the degreeof movement of said bolster yvhen the latter is moved longitudinallywithrespect to said side frames.

31. A car truck comprising a bolster, a side frame associated with oneendlof said bolster, rocker arms pivotally supported on said side frame,springs mounted on substantially horizontal portions of said rockerarms, serving to support the end portion of said bolster, and downwardlyextending friction surfaces interlocked with said. bolster andengagingnpwardlyextending portions of said rocker arms having frictionsurfaces thereon, said rocker arms being pivotally supported at pointsnear the juncture of said subthe same, and means cooperating withreacting with said side frames to restore said bolster to a centralposition after movement thereof longitudinally of said side frames by aforce proportional to the load on said side frames and the extent ofsaid longitudinal movement.

ROY c. Henson.

